The present invention relates to a mechanism of simple structure for adjusting the position of the magnetic head of a VTR, which facilitates the adjustment of the position of the magnetic head relative to a rotation head cylinder and improves the assembly precision.
There has been disclosed in Japanese Utility Model Publication No. 89-38736 a mechanism for adjusting the position of the magnetic head of a VTR which comprises a vertical position adjustment means for confirming the control head (hereinafter referred to as magnetic head) to control the tracking between the sound read/write head and the rotation head and a video recording track to the tape running height, and a horizontal position adjustment means for adjusting the distance between the magnetic head and the rotation head cylinder. In this mechanism, the operation of the vertical position adjustment means does not affect the horizontal position adjustment means.
In such a conventional vertical position adjustment means, there is controlled the pivoting of a head mounting plate that is pivotably mounted on a supporting shaft and upwardly and downwardly movable by means of a pin. In addition, another plate mounted on the supporting plate and upwardly and downwardly movable is biased in one direction by the force of a compression spring that is received by a nut threadedly engaged with the supporting shaft. By means of this nut is adjusted the vertical position. The compression spring presses against the surface of a tapered nut threadedly engaged with the another plate and the head mounting plate. Moreover, because the head mounting plate and the other plate vertically move integrally together even if the vertical position of the magnetic head is adjusted by means of the tapered nut, there is caused no change in the relative position between the head mounting plate and the tapered nut performing the horizontal position adjustment. However, the construction of such a mechanism is complicated.
Moreover, in such a conventional vertical position adjustment mechanisms, because a metal cylindrical member is fixed on one side of the head mounting plate made of a metal by means of a self-locking nut and the magnetic head is mounted on the other side of the head mounting plate so that the self locking nut causes to deteriorate the perpendicularity between the cylindrical member and the head mounting plate, it results that the range of the vertical position adjustment of the magnetic head is increased.